Chair



y 1944. A. LORENZ 2,353,737

CHAIR Filed Sept. 14, 1942v 2 Sheets-Sheet l mmvrom A/vro/v LORENZ 61s A TTORNEX HEY July 18, 1944.

A. LORENZ 2,353,737

CHAIR Filed Sept. 14, 1942 2 Sheets-Sheet 2 l 136' 144 INVENTOR:

. Be A/vmv LORENZ go. I

BY Lu-21:11 V 142 his ATTORQEY Patented July 18, 1944 UNITE D STAT ES PAT EN T OF Ff] CE 11 Claims.

chair of above described type wherein the cushioning action of the resilient means on the swingable seat structure may be readilyadjusted to the weight of the user of thechair.

Another object of my invention is to provide a chair of above described type equipped with means for an easy change from a soft swinging action to a rather stiff swinging action and vice versa.

.A further object of my invention is to provide a chair of above described type, which may be manufactured at low costs.

' In order to carry out my invention in practice I provide a chair comprising a support, a seat structure, a pivotal construction connecting said seat structure with said support for a swinging movement of said seat structure about the pivot of said pivotal construction from a sitting position intoa rearwardly inclined position and from said "rearwardly inclined position into said sitting position, resilient means arranged between said support and said seat structure, said resilient means being movable relative to said seat structure toward and away from said pivotal construction, and adjusting means associated with said resilient means for displacing same relative to the seat structure.

The above mentioned objects and advantages as well as other objects and advantages will be more fully disclosed in the following specification reference being had to the accompanying drawings forming part of this specification, wherein:

Fig. 1 is a side elevational view of a chair according to my invention, parts of one side of the *support being'broken away 'for'a-better disclosure of the'parts'exposed thereby,

Fig. '2 is a sectional view of the chair taken on line 22 of Fig. 1,

Fig. 3 is a diagrammatical view of the seat structure of the chair according to'Fig. lillustratingthe-adjustment of the action of the resilient means on the-seat structure by alvariation ofthe position of the resilient means relative to the seat I structur .Fig. ide a side elevational view or =a; different embodiment of i a ichair according .to 'theiinvention, parts of oneside of the :support being broken away for a better disclosure of the parts exposed thereby,

Fig. 5 is a diagrammatical view of the seat and back-rest of the chair according to Fig. ,4 illustrating the adjustment of the action of .the

resilient means on the seat by .a variation of the relative position between the .back-rest..and the seat,

Figs. 6 and '7 are side elevational views of ,different embodiments of the resilient means arranged between the support and the seat structure of the chair according to the invention,

Fig. 8 is a .top plan view of the resilient means shown in Fig. 7,

Figs. ,9 and 10 are sectional views similar to that shown in "Fig. 2, illustrating, however, a different embodiment of the guiding means for the carriage carrying the resilient means, and

Fig. 11 is a fragmentary side elevational view of a chair according to the invention equipped with a different embodiment of the resilient means.

Referring now to Figs. l -3, 29 generally indicates a support of an'armch'air. The seat structure 22 including'a seat 24 and a back-rest -26 :bymeans of a crank '36 connected .witha shaft 38 carrying a pinion-40 in mesh .with a rack 4:2 secured to the support .20.

1 illustrates the.seatastructureilinthe normal sitting position. If the-user of the chair sits on the chair in rather upright sitting position, the weight of.the user .of'ztheqchairiacts on thepoint 4.4. If the average weight ,of :a user .of

the chair amountsto A pounds; and if the distance between thepoint 44. and the pivot-.28 isa inches,. the loaded seat structure may be 'held in its sitting position .bya spring 30 exerting a force of B poundson the. point Atat a distance of b inches from the pivot.2.8, if the-,amountxof torsion A a equals the .moment ;of torsion B b (see Fig. 3). The spring 3!! acts on ".the

point 46 in the intermediate position shown; in

full lines in Fig. 1. In said position, thespring permits-a mean swinging action :of the seat connected with the support 56 at 58.

structure about the pivot 28 from the substantially horizontal sitting position into a rearwardly inclined position and vice versa, i. e. a swinging action which is neither too "soft nor too stiff.

If an occupant of heavier weight C would sit on the chair and the spring 30 were in the same intermediate position shown in full lines in Fig. l, the seat structure 24 would be slightly rearwardly inclined, as the moment of torsion C a is larger than the moment of torsion Bxb. Furthermore, the swinging action of the seat structure about the pivot 28 would be softer. A-

cording to my invention, however, the action of the spring 39 may be adjusted to the heavier weight C of the occupant by moving the carriage" 32 by means of the crank 35 away from the pivotal construction 28 into such a position, that the spring is brought into the position 38' shown in dash and dot lines in Fig. 1. In said position, the spring acts on the point 48 at a distance 0 from the pivot 28. The distance 0 is larger than the distance I), so that the moment of torsion Cxa equals the moment of torsion B c. Thus, the seat structure loaded by the heavier Weight Cmay be held by the spring 38 in its substantially horizontal sitting position, if the spring is moved into said position 30; moreover, in said position 3-3 the spring permits the same mean swinging action of the seat structure under the heavier weight of an occupant as described above in the full line position under the average weight moving the-spring 30 from the position shown in full lines into the position 30" or 30'.

e As will be apparent from above description, the chair may be readily adjusted to diiierent weights of the occupants by a shifting of the carriage 32 carrying the spring 30. Of course, any other suitable means than the described crank con- :struction, may be used for the displacing of the carriage. As best shownin Fig. 2, the guide 3 3 is of dove-tailed shape so as to prevent a tilting of the carriage 32 under the action of the load on the seat construction.

According to the embodiment shown in Fig. 1,

a single carriage and spring is arranged in the middle of the chair. If desired, however, two springs, one on each side of the chair, mounted on a single carriage or two carriages connected with each other may be arranged in the chair.

In the chair shown in Fig.4, the back-rest 50 'is pivoted to the rear portion of the seat 52 at 54. The front portion of the seat. 52 is pivotally One end of a guiding link generally indicated by 60 is hinged to an intermediate point 62 of the backrest 59, while the other end of said link is hinged to a lug 64 at E6. The lug 64 is slidably mounted on the support 56 and may be adjusted in various positions by means of a clamping device (not shown), the stem 68 of which passes through a slot 10. The link Bil comprises a tube-like member 12 and a rod 14 telescopically connected with each other for a variation in the length of the link. A set screw 16 serves for the adjustment of the length of the link. During a swinging movement of the seat 52 from the substantially horizontal sitting position shown in Fig. 4 into a rearwardiy inclined position the guiding link 60 rotatin about the pivot 56 guides the intermediate point 62 of the back-rest along a continuous circular path, whereby the angle between the seat and the back-rest is increased. If desired, the movable parts of the chair may be held in any suitable position by depressing the locking lever 78.

The swinging movements of the seat 52 are cushioned by a torsional spring having its free end in slidable engagement with the seat and having its other end secured to a carriage 82 reciprocably arranged on a stationary guide mounted on the support 56. The carriage 82 carrying the spring 80 may be displaced in the direction of the longitudinal axis of the chair toward and away from the front portion of the chair by means of a rack and pinion construction 84, 86 as described above in connection with Fig. 2-. A displacement of the carriage 82 serves to adjust the action of the resilient means 80 on the swingable seat 52 to the weight of the occupant in the same manner as described above in connection with Figs. 1 and 3.

According to the embodiment shown in Fig. 4, however, an additional adjustment of the action of the spring 80 on the swingable seat 52 may be carried out. As pointed out above, the guiding link 60 is of adjustable length and the lug 64 may be adjusted to various positions. The length of the guiding link and the position of the lug 64 determine the relative position between the back-rest 50 and the seat 52 in the sitting position of the movable parts of the chair. If, for example, the back-rest is in the position relative to the seat as shown in full lines in Figs. 4 and '5, and if the occupant is in a somewhat reclined position with his back resting on the backrest for the performance of swinging movements of the seat structure, the weight D of the occupant acts on a point of the back-rest at a distance d from the pivot 58, while the force E of the spring 8!] acts on a point of the seat at a distance 0 from the pivot 58. Assume, that under these circumstances the sprin permits a mean swinging action of the seat structure. Now, if the relative position between the backrest and the seat in the sitting position of the movable parts of the chair is changed by turning the back-rest into the position 50' shown in dash and dot lines by an adjustment of the length of the guiding link 60 and/ or the position of the lug 64, the weight D acts on the back-rest at the larger distance 1 from the pivot 58, whereby a softer swinging action of the seat structure is obtained. Likewise, a stifier swinging action may be obtained by turning the back-rest in opposite direction from the full-line position shown in Figs. 4 and 5. Needless to repeat, that further adjustments of the swinging action may be obtained by a lengthwise displacement of the carriage 82 carrying the spring 89.

Fig. 6 illustrates a different embodiment of the resilient means for arrangement on the carriage of a chair according to "Fig. 1 or 4. In this case 2. lug 90 is arranged on a base 92 to be secured to the carriage. One endof a lever 94 is pivoted to the lug 90, the free end of said lever is arranged for .slidable engagement with the seat structure of thechairi JThelever-94 is subjected loose andslidable engagement with said seat to the action of a spring 96 tending to urge the free end of the lever against the seat structure.

Accordingto the embodiment of resilient means shown in Figs. 7 and 8 two torsional springs 98 and I are coaxially arranged around a. shaft I02 carried by two lugs- I04 and I06 mounted on a base I08 to be secured to a carriage. One end of each spring is secured to a lug, and the free end of each spring is arranged for slidable engagement with the seat structure.

Fig. 9 illustrates a different embodiment of the guide-I Ill for a carriage I I2 carrying a spring I I4. In this case, the guide is provided with a groove {116 for engagementwith an extension II8 of the carriagawhereby an riage is prevented. e a

undesired'tiltin of the car- Fig.- 10 illustrates still another embodiment of a guide and carriage. Here, the guide consists of -two parallel bars I and I22in engagement with curved portions I24, I26 of the plate-like carriage I 28 carrying the spring I30.

- While the springs shown in Figs. 1, 4, 6 and '7 fare compressed under the action of the load on the seat, the spring I32 shown in Fig. 11 is stretched during a movement of the seat strucfture I34 from the sitting position into the rearwardly inclined position. an intermediate point of-a lever I36 is pivoted According to Fig. 11

to a lug I38 mounted on a reciprocable carriage I40. One end of the lever I36 is connected with 3 one end ofthe spring I32, the other end of which is secured to the carriage I40. The free end of the lever I36 is in slidable engagement with the seat structure I34 pivotally connected with the support I42 at I44.

As will be readily understood many other embodiments of resilient means and arrangements -for adjusting the position thereof toward or away ment of said seat structure-about the pivot of said L530 pivotal construction from a sitting position into a rearwardly inclined position and from said rearwardly inclined position into said sitting position, a carriage movably arranged on said support, resilient means mounted on said carriage for participating in a movement thereof, said resilient means being in loose and slidable engagement with said seat structure, said carriage being movable relative to said seat structure toward and away from said pivotal construction, and driving means associated with said carriage for displacing same relative to the seat structure.

2. A chair comprising: a support, a seat structure, a pivotal construction connecting said seat structure with said support for a swinging movement of said seat structure about the pivot of said pivotal construction from a sitting position into a rearwardly inclined position and from said rearwardly inclined position into said sitting position, a guide mounted on said support, a carriage slidably arranged on said guide, means associated with said guide for preventing a disengagement of said carriage from said guide, resilient means mounted on said carriage for participating in a movement thereof, said resilient means being in structure, said carriage being movable relative to said seat structure toward and away from said -pivotal construction, and driving means associated with said carriage for displacing same relative to the seat structure.

'3. A chair comprising: a support, a seat structure, a pivotal construction connecting said seat structure with said support for a swinging movement of said seat structure about the pivot of said pivotal construction from a sitting position into a rearwardly inclined position and from said rearwardly inclined position into said sitting position,

a carriage .movably arranged on said support, a

U-shaped spring mounted on said carriage, one

leg of said spring being secured to said carriage, the free leg of said spring being arranged for engagement with said seat structure, said carriage being'mov'able relative to said seat structure toward and away from said pivotal construction, and adjusting'means associated with said carriage 'for displacing same relative to the seat structure, said carriage being movable relative to said seat structure toward and away from said pivotal construction, and adjusting means associated with said carriage for displacing same relative to the seat structure.

5. A chair comprising: a support, a seat structure, a pivotal construction connecting said seat structure with said support for a swinging movement of said seat structure about the pivot of said pivotal construction from a sitting position into a rearwardly inclined position and from said rearwardly inclined position into said sitting position, a carriage movably arranged on said support, a torsional spring mounted on said carriage, oneend of said torsional spring being secured to said carriage, the free-end of said torsional spring being arranged for engagement with said seat structure, said carriage being movable relative to said seat structure toward and away from said pivotal construction, and adjusting means associated with said carriage for displacing same relative to the seat structure.

6. A chair comprising: a support, a seat, a backrest, a pivotal construction connecting said seat with said support for a swinging movement of said seat about the pivot of said pivotal construction from a sitting position into a rearwardly inclined position and from said rearwardly inclined position into said sitting position, said back-rest being pivoted to said seat, guiding link-means associated with said back-rest for a.contro1 of the angle between said back-rest and said seat in dependence on a swinging movement of the seat, a carriage movably arranged on said support, resilient means mounted on said carriage for participating in a movement thereof, said resilient means being in loose and slidable engagement with said seat, said carriage being movable relative to said seat toward and away from said pivotal construction, and driving means associated with said carriage for displacing same relative to the seat.

7. A chair comprising: a support, a seat, a backrest, a pivotal construction connecting the front portion of said seat with said support for a swinging movement of said seat about the pivot of said intermediate point of said back-rest, said intermediate point of the back-rest being guided along a continuous circular path by said guiding linkmeans during aswingin movement of said seat whereby the angle between the seat and the backrest is increasedwhen the seat is swung from the I sitting position into the rearwardly inclined position, a carriage movably arranged on said support,

resilient means mounted on said carriage for participating in a movement thereof, said resilient omeans being in loose and slidable engagement with said seat, said carriage being movable relative to said seat toward and away from said pivotal construction, and driving means associated with said carriage for displacing same relative to the seat. I V

8. A chair comprising: a support, a seat, a back-rest, a pivotal construction connecting the front portion of said seat with said support for a swinging movement of said seat about the pivot of said pivotalconstruction from a sitting position into a rearwardly inclined position and from said I rearwardly inclined position into said sitting position, said back-rest being pivoted to the rear portion of said seat, adjustable guiding linkmeans, one end of said adjustable guiding linkmeans being pivoted to said support at a point tioned not higher than the horizontal plane of said front pivot of the seat, the other end of said vadjustable guiding link-means being hinged to an intermediate point of said back-rest, said inter mediate point of the back-rest being guided along a continuous circular path by said adjustable guiding link-means during a swinging movement of said seat whereby the angle bet-ween'the seat and the back-rest is increased when the seat is swung from the sitting position into the rearwardly in- .clined position, a carriage movably arranged on said support, resilient means mounted on said spaced from the front pivot of the seat and posicarriage for participating in a movement thereof,

said resilient means being in loose and slidable engagement with said seat, said carriage being movable relative to said seat toward and away from said pivotal construction, and driving means associated with said resilient means for displacing same relative to the seat.

9. A chair as claimed in claim 8 including guiding link-means of variable length, and means for adjusting the length of said guiding link-means for a preadjustment of the relative position between the back-rest and the seat. 7

10. A chair as claimed in claim 8 comprising movable pivotal means between the support and the adjustable guiding link-means, and means .for adjusting the relative position between said pivotal means and said support for a preadjustment of the relative position between the backrest and the seat.

' 11. A chair comprising: a support, a seat, a back-rest, a pivotal construction connecting the front portion of said seat with said support for a swinging movement of said seat about the pivot of said pivotal construction from a. sitting position into a rearwardly inclined position and from said rearwardly inclined position into said sitting position, said back-rest being pivoted to the rear portion of said seat, guiding link-means, one end of said guiding link-means being pivoted to said support at a point spaced from the front pivot of the seat and positioned not higher than the horizontal plane of said front pivot of the seat, the other end of said guiding link-means being hinged to an intermediate point of said back-rest, said intermediate point of the back-rest being guided along a continuous circular path by said guiding link-means during. a swinging movement of said seat whereby the angle between the seat and the back-rest is'increased when the seat is sw ng from the sitting position into the rearwardly inclined position, a carriage movably arranged on said support, resilient means mounted on said carriage for participating in a movement thereof, said resilient means being in loose and slidable engagement with said seat, said carriage being movable relative to said seat toward and away from said pivotal construction, adjusting means associated with said carriage for displacing same relative to the seat, and locking means associated with the movable parts of the chair for locking same in a desired position. I

ANTON LORENZ. 

